What is the future of space travel?

In the 50 years since the Apollo 11 Moon landing, humans have made extraordinary progress in space exploration. But what is the next giant leap for crewed spaceflight – and could 'space tourism' soon become a reality?

Right now, unmanned space probes are exploring the universe far beyond our solar system, communicating with Earth from over 11 billion miles away. We have also developed technologies that allow humans to survive in space for lengthy durations, with Russian cosmonaut Valeri Polyakov holding the record for the longest single stay in space - a remarkable 437 days aboard the Mir space station.

Human or robotic space exploration?

We asked two of our astronomers: should we be spending our money on human or robotic space exploration?

What is the future of space exploration?

The Cold War 'Space Race' between the USA and Soviet Union ended in the 1970s. Today the landscape is very different, with multiple countries engaged in current and future space missions.

"Make no mistake about it: we're in a space race today, just as we were in the 1960s, and the stakes are even higher," US Vice President Mike Pence said during a speech in March 2019.

Currently there are over 70 different government and intergovernmental space agencies. Thirteen of these have space launch capabilities, including NASA, the European Space Agency (ESA), the Russian Federal Space Agency (Roscosmos) and the China National Space Administration (CNSA).

However, government space agencies are only part of the story when it comes to 21st century space travel. A number of commercial companies are also developing spaceflight capabilities, including SpaceX founded by Elon Musk, Blue Origin established by Amazon CEO Jeff Bezos, and Richard Branson's Virgin Galactic. By 2030, it has been estimated that the global space market could be worth £400 billion.

Both space agencies and commercial companies have a number of different objectives for the next 50 years, including:

Automated and robotic exploration of the Solar System and beyond

Telescopic exploration of deep space

Development of innovative spacecraft

Crewed spaceflight and settlements on planets

Space tourism

Mining of other planets.

Back to the Moon

As the closest celestial body to Earth, missions to the Moon are seen by many scientists and engineers as an essential starting point for voyages to more distant planets. The Moon may prove useful as a space station or testing ground for humans to learn how to replenish supplies, before looking to settle on distant planets such as Mars.

NASA has been set the ambitious goal of returning humans to the Moon by 2024 and establishing a sustainable human presence on the Moon by 2028. The US space agency is working with a number of international and commercial partners, including the European Space Agency, in order to achieve this. The mission is called Project Artemis: the goddess Artemis was the twin sister of Apollo in Greek mythology. Among the stated goals of the NASA mission is an aim to land the first woman on the Moon.

However, the United States is not the only country with lunar ambitions. China is planning a crewed mission to the Moon's south pole by 2030, and has already successfully landed a robotic rover on the Moon's far side.

India meanwhile launched a combined lunar orbiter, lander and rover on 22 July 2019, in a mission known as Chandrayaan-2. On 7 September 2019, the ISRO space station lost contact with the Vikram lunar lander, as it was just 2km from the lunar surface.

In September 2019 Elon Musk revealed a prototype of his Starship rocket, claiming it would be ready to take off in one to two months, reaching 19,800 metres before returning to Earth.

Future spacecraft

Organisations both public and private are looking to develop more sustainable ways of building and launching spacecraft for future missions, in order to overcome the major obstacle in space exploration: the astronomical costs involved.

One example of these innovations is the development of a new space capsule called Orion, managed by both NASA and the European Space Agency. The flexibility of the vehicle is designed to take astronauts to and from the International Space Station and also enable repeat landings on the Moon's surface. The Orion spacecraft was first launched in an uncrewed flight in December 2014, and it is intended to be the craft used during the Artemis missions to the Moon scheduled from 2020.

Artist depiction of the Orion module in space (Credit: NASA)

Robotic exploration

As machines become increasingly capable of independently performing tasks, many organisations are looking to prioritise robotic over human spaceflight. These machines are designed for specific tasks and can withstand the extreme conditions of space.

NASA's Mars Curiosity Rover is a prime example of this. Launched on 26 November 2011, the robotic vehicle landed on the surface of Mars on 5 August 2012 and has been exploring the Martian landscape ever since. It even has its own Twitter account, keeping millions of followers up to date with its latest scientific observations.

Something in the air tonight

I detected the largest amount of methane ever during my mission: ~21 parts per billion by volume. While microbial life can be a source of methane on Earth, methane can also be made by interaction between rocks and water. https://t.co/CPEpxsspR2pic.twitter.com/uk2mjV7OeE

Space tourism

In the last decade, companies such as Virgin Galactic, Airbus and Blue Origin have begun developing commercial spacecraft to send private customers into space. Currently, businesses are taking reservations for trips into the upper atmosphere, where patrons can experience zero-gravity and observe the curvature of the Earth. NASA has also announced plans to allow private individuals to visit the International Space Station, with the first flights scheduled for 2020.

Five future space missions

Name: Parker Solar Probe

Type: Probe

Launched: 12 August 2018

Operator: NASA

The Parker Solar Probe is named after astrophysicist Eugene Parker. While already launched, the probe won’t reach its objective - the Sun - until 2025. Its mission is to obtain observations of the Sun and provide accurate data on solar winds (charged particles that escape from the Sun) and why they exist. The probe is built to withstand the 1377°C heat from the Sun at a distance of almost 95 million miles, seven times closer than any spacecraft before it.

This planned Chinese project aims to follow-up on its success of landing a probe on the far side of the Moon with its second mission to Mars in 2020. The stated objective of the HX-1 rover project is to land on Mars and search for the presence and potential for life on the Martian planet. It could also provide essential information as to the potential for crewed flights to Mars in the future.

Name: James Webb Space Telescope (JWST)

Type: Telescope

Launch: March 2021

Operator: NASA, ESA & CSA

Named after James Webb, the administrator at NASA during the Mercury and Gemini space programmes, this telescope will search for the first galaxies after the Big Bang. Furthermore, the use of infrared imaging will aid scientists in understanding the physical and chemical properties of these star systems, including the observation of some of the most distant events and objects in the universe.

Name: Starship

Type: Rocket

Launch: First commercial missions scheduled for 2021

Operator: SpaceX

The private company, SpaceX, is developing a powerful spacecraft and rocket system that could eventually be used to take humans to the Moon and Mars. With a potential carrying capacity of 100,000 kilograms, the rocket is designed to carry much larger payloads and crew numbers into space. Originally known as the Big Falcon Rocket, founder Elon Musk renamed the craft in November 2018, calling the transportation part of the vehicle 'Starship' and the rocket section 'Super Heavy'. Along with other SpaceX spacecraft and rocket systems, the project is aiming to be reusable, reducing the costs of future space exploration.

Name: Breakthrough Starshot

Type: Spacecraft

Launch: Around 2036

Operator: Breakthrough Initiatives

Breakthrough Starshot is a bold engineering project aiming to send 1000 tiny spacecraft to Alpha Centauri in a journey lasting 20 years. The mission intends to test the possibility of ultra-fast space travel (15-20 per cent of the speed of light), and achieve interstellar travel. However, the project is still very much in its infancy.

Why have we not been back to the Moon?

US astronaut Eugene Cernan is the last human to have walked on the Moon. He and fellow Apollo 17 astronaut Harrison Schmitt left the lunar surface on 14 December 1972. Since then, human crews have not returned.

However, many probes have been sent to the Moon in the decades since, including missions by Indian, Chinese and European space agencies.

One of the main reasons for the lack of crewed missions to the Moon is the cost. The Apollo missions cost roughly $200 billion (£160bn) in today's money. Even following a funding boost, NASA's annual budget for 2019 was $21.5 billion (£17.25bn).

Commercial space companies have changed the economics of space exploration, but for both private companies and national agencies the long-term objectives of future space missions need to be more innovative than simply repeating a historical mission. Current missions to the Moon are aiming to explore new regions of the lunar surface, including its far side and its south pole. Crewed missions are also designed to be part of a longer term process of exploring further into space, beginning with Mars.

How much does it cost to go into space?

The high cost of leaving the Earth is the major obstacle to further exploration of space. Currently for example, only the Russian Soyuz rocket is able to transport astronauts to the International Space Station, with NASA paying a reported $75 million (£60m) per seat in 2017.

When NASA's space shuttle programme was in operation between the 1980s and mid-2000s, it could carry a payload of 27,500 kilograms for an average cost per flight of $1.5 billion (£1.2bn). This cost has reduced with the collaboration of private companies: a SpaceX Falcon 9 rocket can launch 22,800kg into low Earth orbit for a published cost of $62 million (£50m).

Once in space, the costs remain high. The International Space Station has been dubbed the most expensive machine ever constructed, with an estimated total cost since since its first launch in 1998 of $150 billion (£120bn).

How much would a flight into space cost me?

Depending on where in space you're going, a ticket aboard a commercial spacecraft could cost from $250,000 to tens of millions of dollars.

Private company Virgin Galactic is offering 'space tourists' the chance to cross the boundary between the upper atmosphere and outer space (known as the Karman Line at 62 miles above the Earth). A place on the flight costs a reported $250,000 (£200,600), and more than 600 people are said to have bought tickets.

NASA announced in 2019 that it would be opening up the International Space Station to private individuals from 2020, with an estimated cost of $35,000 (£28,000) per day. However, this does not include the cost of the spaceflight itself, which is set to be run by private companies SpaceX and Boeing and could cost over $60 million (£48m) per flight.

The world's first private astronaut Dennis Tito paid a reported $20 million (£16m) to join the Soyuz TM-32 mission on 28 April 2001. The American businessman spent nearly eight days in space aboard the International Space Station. The trip was booked with a space tourism company called Space Adventures Ltd.

Dennis Tito, the world's first space tourist with pilots of the Soyuz TM-32, Talgat Musabayev and Yuri Baturin (source: Wikicommons)